At about 7 am on Sunday morning, Otis Tyrone McKane walked through the front doors of the San Antonio Police Department Public Safety Headquarters, a fortress-like complex at the corner of Santa Rosa and Cesar Chavez that houses administrative and investigative offices for both the local police and fire departments.

McKane, wearing a hoodie and a black and white Spurs cap, approached a service agent in the lobby and asked to speak with someone about a child custody issue. But when the agent asked some follow-up questions, McKane seemed to lose interest and abruptly exited the building, walked around the block, and got into a black Mitsubishi Galant he'd parked across the street in a private lot. Police would later note that the car had one distinctive feature: aftermarket black spoke rims.

The first bullet hit the 20-year SAPD veteran in the face. Video from inside the cruiser shows Marconi was slumped over in his seat as the suspect reached inside the window, placed the gun barrel near the back of the officer's head, and again pulled the trigger. An arrest warrant affidavit filed in the case, which details the 24-hour manhunt that ultimately led to McKane's arrest on Monday, calls that second shot evidence of McKane's "intention to execute Detective Marconi."

It was McKane's Spurs cap and the rims on his car that ultimately led to his arrest Monday afternoon, according to the affidavit filed with his capital murder case. While the camera inside Marconi's cruiser didn't capture the suspect's face, that Spurs hat showed up on the video "in a brief reflection," according to the affidavit. Police on Sunday eventually gave reporters grainy surveillance images of the man in the Spurs hat who'd entered police headquarters hours before the shooting. They also distributed images of the suspect's black car.

SAPD

Surveillance video showed a man police have identified as McKane walking into police headquarters hours before the fatal shooting

It appears two lucky breaks ultimately helped police track down McKane on Monday, according to the affidavit filed in court. At around 10:30 Monday morning, an SAPD officer responding to an unrelated call on the Westside spotted a car that looked just like the photos of McKane's black Mitsubishi. At around the same time that morning, a man working with a local tire rental business contacted investigators to say he recognized both the suspect and the car that he'd seen on the news. The man told police he'd sold McKane the rims and tires several weeks ago, but that McKane still often stopped in at the shop because he was on a payment plan.

On Monday, San Antonio Police Chief William McManus told reporters that investigators tracked McKane for about three hours before a SWAT team swooped in to arrest him. But before any of that, as the Express-News first reported, McKane somehow managed to get married at the downtown county courthouse while investigators were still connecting the dots.

In his perp walk Monday evening, McKane told reporters he'd been in "several custody battles" and just wanted to see his son. When asked why he targeted a cop, here's how he put it: "I lashed out at someone who didn’t deserve it."